JPH0684602A - Thin film resistor material - Google Patents
Thin film resistor materialInfo
- Publication number
- JPH0684602A JPH0684602A JP4254047A JP25404792A JPH0684602A JP H0684602 A JPH0684602 A JP H0684602A JP 4254047 A JP4254047 A JP 4254047A JP 25404792 A JP25404792 A JP 25404792A JP H0684602 A JPH0684602 A JP H0684602A
- Authority
- JP
- Japan
- Prior art keywords
- thin film
- strain gauge
- resistor material
- strain
- film resistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Non-Adjustable Resistors (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、外部からの応力によっ
て誘起された歪による電気抵抗変化を利用した素子等の
材料に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for an element or the like which utilizes a change in electric resistance due to strain induced by external stress.
【０００２】[0002]
【従来の技術】各種構造体の変形量を検知するセンサー
（以下、歪ゲージ）は、土木・建築・機械などの分野に
おいて広く用いられている。一般の歪ゲージは、金属抵
抗体を絶縁体を介して被測定物に固定し、被測定物の変
形により歪ゲージの抵抗値が変化することから被測定物
の変形量を知ることが出来る。歪ゲージ用抵抗体に要求
される条件の主なものは、（１）抵抗変化率（△Ｒ／
Ｒ）は歪εに比例し、△Ｒ／Ｒ＝Ｋ・εで定義される比
例定数Ｋ（以下ゲージ率）が大きく、測定歪範囲内で一
定であること。（２）弾性限界が大きく、疲労強度が大
きいこと。（３）抵抗温度係数が広い温度範囲にわたり
小さいこと。（４）比抵抗が大きいこと。等である。2. Description of the Related Art Sensors (hereinafter, strain gauges) for detecting the amount of deformation of various structures are widely used in the fields of civil engineering, construction, machinery and the like. In a general strain gauge, a metal resistor is fixed to an object to be measured through an insulator, and the resistance value of the strain gauge changes due to deformation of the object to be measured, so that the deformation amount of the object to be measured can be known. The main requirements for the strain gauge resistor are (1) resistance change rate (ΔR /
R) is proportional to the strain ε, and the proportional constant K (hereinafter, gauge factor) defined by ΔR / R = K · ε is large and constant within the measured strain range. (2) Large elastic limit and large fatigue strength. (3) The temperature coefficient of resistance is small over a wide temperature range. (4) Large specific resistance. Etc.
【０００３】歪ゲージ用抵抗体には形態によって分類す
れば、細線状のものと薄膜状のものの二種類がある。前
者は金属材料のうちでも加工性に優れるＮｉ−Ｃｕ系、
Ｎｉ−Ｃｒ系などの材料であり、２５μｍ程度以下まで
ダイス引き等によって容易に径を小さくでき、ゲージ
長、ゲージ巾として所望のものを選びやすいという製造
上の利点がある。しかし一方、これらの材料系では弾性
限界が小さいという欠点がある。ＣｕＮｉ、ＮｉＣｒお
よびＰｔＩｒの弾性限界、比抵抗およびゲージ率を表１
に示す。The strain gauge resistors are classified into two types, that is, a thin wire type and a thin film type, according to the form. The former is a Ni-Cu system that is excellent in workability among metallic materials,
It is a material such as Ni-Cr system, and has a manufacturing advantage that the diameter can be easily reduced to about 25 μm or less by die drawing and the desired gauge length and gauge width can be easily selected. On the other hand, however, these material systems have a drawback that the elastic limit is small. Table 1 shows elastic limits, specific resistances and gauge factors of CuNi, NiCr and PtIr.
Shown in.
【０００４】[0004]
【表１】 [Table 1]
【０００５】すなわち、表１によれば、各合金とも弾性
限界範囲は高々０．４％であり、これを上回るような繰
り返し歪の測定に適する材料はない。そこで、弾性限界
を越えて変形しても応力を除去すればもとの形状に回復
する例えばＮｉ−Ｔｉ系合金を歪ゲージ用抵抗材料とし
て用いることが考えられる。ところが、この組成系の材
料は伸線加工による延靭性の劣化が著しい。例えばダイ
スによる冷間伸線の減面率はステンレスなどの通常材で
は９０％以上の加工が可能であるのに対し、ＮｉＴｉ合
金では４５〜５０％が限界である。そのため細線を加工
するには軟化熱処理を繰り返す必要があり、極細線を得
るには相当の回数の熱処理を行わなければならず、製造
工程・製造コストの増加は避けられない。さらに、材料
中の酸素、炭素、窒素などの不純物元素は冷間加工性の
劣化を惹起し、特に直径１００μｍ以下の細線ではその
影響は顕著であり、しばしば伸線時に断線の原因とな
る。一般に歪ゲージでは歪ゼロの状態で、ある一定の抵
抗値をもつように設計がなされているが、細線状の抵抗
体を用いる場合にその加工性が劣ることによる形状の制
限はゲージ幅・ゲージ長を決定する上でマイナスとな
り、歪ゲージの小型化の阻碍となる。That is, according to Table 1, the elastic limit range of each alloy is at most 0.4%, and there is no material suitable for measuring the cyclic strain that exceeds the elastic limit range. Therefore, it is conceivable to use, for example, a Ni—Ti-based alloy, which recovers its original shape when the stress is removed even if it deforms beyond the elastic limit, as a resistance material for a strain gauge. However, the material of this composition is significantly deteriorated in ductility due to wire drawing. For example, the surface reduction rate of cold drawing with a die can be processed to 90% or more with a normal material such as stainless steel, whereas the NiTi alloy has a limit of 45 to 50%. Therefore, the softening heat treatment needs to be repeated to process the fine wire, and the heat treatment must be performed a considerable number of times to obtain the ultrafine wire, and an increase in the manufacturing process / manufacturing cost cannot be avoided. Further, impurity elements such as oxygen, carbon, and nitrogen in the material cause deterioration of cold workability, and particularly in a fine wire having a diameter of 100 μm or less, the effect is remarkable, and often causes a break in the wire drawing. In general, strain gauges are designed to have a certain resistance value when the strain is zero, but when using a fine wire resistor, the workability is poor. It is a negative factor in determining the length, which prevents the strain gauge from becoming smaller.
【０００６】また、薄膜状の歪ゲージ用抵抗材料として
は金属または合金の歪抵抗変化を利用するもののほか
に、Ｓｉのような半導体のピエゾ抵抗効果を利用するも
のがある。しかしながらＳｉはゲージ率は大きいが、電
気抵抗の温度係数が大きく、歪抵抗特性の直線性が悪
い。その結果、歪ゲージ出力の直線性を改善するための
増幅器・温度補償回路を必要とし、制御系が複雑化する
という難点がある。さらに半導体のピエゾ抵抗効果を利
用する半導体材料は抵抗変化を利用する金属材料に比べ
弾性限界値が表１の金属製のものよりもさらに小さく、
変形量の大きい構造体の歪測定用の歪ゲージとしては不
向きである。Further, as the thin-film strain gauge resistance material, there is a material utilizing the strain resistance change of a metal or an alloy, and a material utilizing the piezoresistance effect of a semiconductor such as Si. However, although Si has a large gauge factor, the temperature coefficient of electric resistance is large, and the linearity of the strain resistance characteristic is poor. As a result, an amplifier and a temperature compensating circuit are required to improve the linearity of the strain gauge output, and the control system becomes complicated. Further, the semiconductor material utilizing the piezoresistive effect of the semiconductor has an elastic limit value smaller than that of the metal material of Table 1, as compared with the metal material utilizing the resistance change.
It is not suitable as a strain gauge for strain measurement of a structure having a large amount of deformation.
【０００７】また、金属薄膜の歪ゲージ用抵抗材料とし
ては細線に使用される材料がそのまま用いられることが
多く、表１に示した長所・短所はほぼそのまま受け継が
れる。結局、弾性限界が大きく、かつ歪ゲージとした場
合に小型化の可能な抵抗材料は従来存在しなかった。Further, as the resistance material for the strain gauge of the metal thin film, the material used for the thin wire is often used as it is, and the advantages and disadvantages shown in Table 1 are almost inherited. After all, there has not been a resistance material that has a large elastic limit and can be downsized when used as a strain gauge.
【０００８】[0008]
【発明が解決しようとする課題】近年、構造材料の強度
に対する要求特性が高まり、変形率が数％に達する例え
ば、複合材料であるが、ガラス繊維強化プラスチック
（ＧＦＲＰ）やアルミナ繊維強化プラスチック（ＡＦＲ
Ｐ）のような構造材料が開発・実用化されようとしてい
る。このような材料の繰り返し試験に従来の歪ゲージを
用いた場合、歪ゲージ出力に零点ドリフトが生じてしま
う。このような巨大な歪領域では通常用いられてきた金
属製の歪ゲージ抵抗体においては、弾性限界を越えて塑
性変形が生じ、荷重を除去しても永久変形が金属抵抗体
に残り、零点ドリフトの原因となる。このため前述のよ
うな変形量の大きい材料の繰り返し試験には従来の歪ゲ
ージを使用することが出来ず、特殊な変位計が用いられ
る。しかし、このような変位計は歪ゲージに比べ、大型
かつ高価であり、感度も不十分である。また、被測定体
の形状を著しく限定するなどの問題点がある。In recent years, the demand for strength of structural materials has increased, and the deformation rate reaches several percent. For example, composite materials such as glass fiber reinforced plastic (GFRP) and alumina fiber reinforced plastic (AFR) are used.
Structural materials such as P) are about to be developed and put to practical use. When a conventional strain gauge is used for the repeated test of such a material, zero point drift occurs in the strain gauge output. In metal strain gauge resistors, which are usually used in such a huge strain region, plastic deformation occurs beyond the elastic limit, and even if the load is removed, permanent deformation remains in the metal resistor and zero-point drift occurs. Cause of. Therefore, the conventional strain gauge cannot be used for the repeated test of the material having a large amount of deformation as described above, and a special displacement gauge is used. However, such a displacement gauge is larger and more expensive than a strain gauge, and its sensitivity is insufficient. There is also a problem that the shape of the object to be measured is extremely limited.
【０００９】[0009]
【課題を解決するための手段】上述の問題点を解決する
手段として、本発明者は超弾性特性を示すＮｉ−Ｔｉ系
合金について、スパッタリング等の物理的蒸着法によっ
て薄膜状の歪ゲージ用抵抗材料を得て、これが細線状の
歪ゲージ用抵抗材料と同等の歪抵抗特性を示すことを見
いだした。即ち本発明は、１．歪ゲージに用いられる薄
膜抵抗材料であって、外部からの応力によって誘起され
た歪が０％以上７％以下の範囲において、電気抵抗が一
定の変化を示すことを特徴とする薄膜抵抗材料であり、
２．前記薄膜抵抗材料は、Ｎｉ４８〜５２原子％、残余
実質的にＴｉが分布した薄膜であることを特徴とする請
求項１記載の薄膜抵抗材料であり、３．前記薄膜抵抗材
料は物理的蒸着法によって形成され、膜厚が０．０１〜
３０μｍであることを特徴とする請求項１および請求項
２記載の薄膜抵抗材料である。As a means for solving the above-mentioned problems, the present inventor has developed a thin-film strain gauge resistor for a Ni--Ti alloy exhibiting superelastic characteristics by a physical vapor deposition method such as sputtering. After obtaining a material, it was found that it exhibits strain resistance characteristics equivalent to those of a resistance material for a thin wire strain gauge. That is, the present invention is as follows. A thin film resistance material used for a strain gauge, which is characterized in that electric resistance shows a constant change in a range of 0% to 7% of strain induced by external stress. ,
2. 2. The thin film resistance material according to claim 1, wherein the thin film resistance material is a thin film in which Ni is 48 to 52 atomic% and the balance is substantially Ti. The thin film resistance material is formed by physical vapor deposition and has a film thickness of 0.01 to
The thin film resistance material according to claim 1 or 2, wherein the thickness is 30 μm.
【００１０】[0010]
【作用】弾性限度を越えて変形しても、応力を除去すれ
ば元の形状に回復する超弾性効果を有するＴｉ−Ｎｉ合
金を、歪ゲージ用抵抗体とすることにより、７％以内の
変形率であれば零点ドリフトなく再現性よく測定可能と
し、かつ該抵抗体を薄膜化することによって、細線加工
の困難性を克服した。Function: Deformation within 7% by using a Ti-Ni alloy, which has a superelastic effect that recovers the original shape when stress is removed even if it deforms beyond the elastic limit, as a strain gauge resistor. If the ratio is high, measurement can be performed with good reproducibility without zero-point drift, and the thinning of the resistor overcomes the difficulty of fine line processing.
【００１１】[0011]
【実施例】図１は本発明の実施例の試作した歪ゲージの
平面図である。以下、本発明の実施例を実験結果にもと
づいて説明する。図１に示すように、Ｎｉ−Ｔｉ合金タ
ーゲットをＲＦマグネトロンスパッタ装置に装着し、真
空槽内を７．０×１０-7Ｔｏｒｒまで排気した後、Ａｒ
ガスを真空槽内に導入し基板１上にＮｉ−Ｔｉ合金薄膜
２を成膜した。このときＡｒガス圧を３ｍＴｏｒｒ、投
入電力を１．３Ｗ／ｃｍ2、スパッタ時間を８分間と
し、基板１として結晶化ガラスおよびポリミイドフィル
ムを用いた。組成の異なるＮｉ−Ｔｉ合金ターゲットを
用いることにより６種類の組成のＮｉ−Ｔｉ合金薄膜を
得た。Ｘ線分析装置（ＥＤＸ）により分析した膜組成を
表２に示している。また、触針式表面粗さ計によって膜
厚を測定したところ、約０．２μｍであった。さらに電
極用マスクを取り付けた上でスパッタリング装置でＡｕ
ターゲットに１．３Ｗ／ｃｍ2のＲＦ電力を印加し、Ａ
ｕ電極膜３を０．１μｍの厚さで形成した。このＡｕ電
極膜３にリード線４を半田付けし、図１に示す形状の試
料を得、膜厚、ゲージ率、使用限界変形率を測定したと
ころ、表２のような結果を得た。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view of a prototype strain gauge of an embodiment of the present invention. Hereinafter, examples of the present invention will be described based on experimental results. As shown in FIG. 1, a Ni—Ti alloy target was attached to an RF magnetron sputtering apparatus, the inside of the vacuum chamber was evacuated to 7.0 × 10 −7 Torr, and then Ar was used.
Gas was introduced into the vacuum chamber to form the Ni—Ti alloy thin film 2 on the substrate 1. At this time, the Ar gas pressure was 3 mTorr, the input power was 1.3 W / cm 2 , the sputtering time was 8 minutes, and the crystallized glass and the polymide film were used as the substrate 1. By using Ni-Ti alloy targets having different compositions, Ni-Ti alloy thin films having 6 kinds of compositions were obtained. The film composition analyzed by the X-ray analyzer (EDX) is shown in Table 2. Further, the film thickness was measured by a stylus type surface roughness meter, and it was about 0.2 μm. Furthermore, after attaching an electrode mask, Au was used with a sputtering device.
RF power of 1.3 W / cm 2 was applied to the target, and A
The u electrode film 3 was formed to a thickness of 0.1 μm. The lead wire 4 was soldered to the Au electrode film 3 to obtain a sample having the shape shown in FIG. 1, and the film thickness, gauge ratio, and use limit deformation ratio were measured, and the results shown in Table 2 were obtained.
【００１２】[0012]
【表２】 [Table 2]
【００１３】[0013]
【発明の効果】本発明によれば、７％程度以内の繰り返
し歪の測定に適する歪ゲージ用薄膜抵抗体を容易に得る
ことが出来る。According to the present invention, it is possible to easily obtain a strain gauge thin film resistor suitable for measuring a repeated strain within about 7%.
【図１】本発明の実施例に於て試作した歪ゲージの平面
図。FIG. 1 is a plan view of a strain gauge prototyped in an embodiment of the present invention.
１ 基板 ２ Ｎｉ−Ｔｉ合金薄膜 ３ Ａｕ電極膜 ４ リード線 1 Substrate 2 Ni-Ti alloy thin film 3 Au electrode film 4 Lead wire
Claims (3)
って、外部からの応力によって誘起された歪が０％以上
７％以下の範囲において、電気抵抗が一定の変化を示す
ことを特徴とする薄膜抵抗材料。1. A thin film resistance material used for a strain gauge, characterized in that the electric resistance exhibits a constant change in a range where strain induced by external stress is 0% or more and 7% or less. Thin film resistance material.
子％、残余実質的にＴｉが分布した薄膜であることを特
徴とする請求項１記載の薄膜抵抗材料。2. The thin film resistance material according to claim 1, wherein the thin film resistance material is a thin film in which Ni is 48 to 52 atomic%, and the balance is substantially Ti.
て形成され、膜厚が０．０１〜３０μｍであることを特
徴とする請求項１および請求項２記載の薄膜抵抗材料。3. The thin film resistance material according to claim 1, wherein the thin film resistance material is formed by a physical vapor deposition method and has a film thickness of 0.01 to 30 μm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4254047A JPH0684602A (en) | 1992-08-28 | 1992-08-28 | Thin film resistor material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4254047A JPH0684602A (en) | 1992-08-28 | 1992-08-28 | Thin film resistor material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0684602A true JPH0684602A (en) | 1994-03-25 |
Family
ID=17259499
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4254047A Pending JPH0684602A (en) | 1992-08-28 | 1992-08-28 | Thin film resistor material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0684602A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7752927B2 (en) | 2008-01-22 | 2010-07-13 | Hitachi Cable, Ltd. | Cable-type load sensor |
| WO2010138813A3 (en) * | 2009-05-29 | 2011-02-17 | The Board Of Trustees Of The University Of Illinois | High resolution large displacement/crack sensor |
| WO2019124019A1 (en) * | 2017-12-20 | 2019-06-27 | 国立大学法人筑波大学 | Curvature detection sensor |
-
1992
- 1992-08-28 JP JP4254047A patent/JPH0684602A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7752927B2 (en) | 2008-01-22 | 2010-07-13 | Hitachi Cable, Ltd. | Cable-type load sensor |
| WO2010138813A3 (en) * | 2009-05-29 | 2011-02-17 | The Board Of Trustees Of The University Of Illinois | High resolution large displacement/crack sensor |
| US9109883B2 (en) | 2009-05-29 | 2015-08-18 | The Board Of Trustees Of The University Of Illinois | High resolution large displacement/crack sensor |
| WO2019124019A1 (en) * | 2017-12-20 | 2019-06-27 | 国立大学法人筑波大学 | Curvature detection sensor |
| JPWO2019124019A1 (en) * | 2017-12-20 | 2020-12-17 | 国立大学法人 筑波大学 | Curve detection sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6022881B2 (en) | Strain gauge | |
| EP0035351B1 (en) | Deformable flexure element for strain gage transducer and method of manufacture | |
| CN109825809A (en) | A kind of polyimide-based resistance-type thin film strain sensors and the preparation method and application thereof | |
| US4100524A (en) | Electrical transducer and method of making | |
| EP0359132B1 (en) | Thin film resistor for strain gauge | |
| JP2001221696A (en) | Temperature-sensitive and strain-sensitive composite sensor | |
| JP2019192740A (en) | Strain resistance film, strain sensor, and manufacturing method thereof | |
| JPH0684602A (en) | Thin film resistor material | |
| DE3522427A1 (en) | Titanium oxynitride layer for use in sensors | |
| JPH0666162B2 (en) | Thin film resistor for strain gauge | |
| JP4988938B2 (en) | Temperature sensitive strain sensor | |
| JPH01202601A (en) | Metal thin film resistance strain gauge | |
| JP2022074104A (en) | Strain gauge and manufacturing method thereof | |
| Bethe et al. | Thin-film strain-gage transducers | |
| CN112710405B (en) | Temperature sensor | |
| JPH06258010A (en) | Strain gauge | |
| JP2562610B2 (en) | Thin film resistor for strain gauge | |
| JP2838361B2 (en) | Pressure sensor integrated pressure sensor | |
| Nayak et al. | Diaphragm-type sputtered platinum thin film strain gauge pressure transducer | |
| JPH0276201A (en) | Thin film resistor for strain gauge | |
| JP2001110602A (en) | Thin-film resistor forming method and sensor | |
| EP4317926A1 (en) | Strain-resistance film and pressure sensor | |
| EP1247068A1 (en) | Self-compensated ceramic strain gage for use at high temperatures | |
| US20240175773A1 (en) | Distortion resistance film and pressure sensor | |
| EP4350313A1 (en) | Strain resistance film, physical quantity sensor, and method for manufacturing the strain resistance film |